Built by Marshall Field and Company, the massive Chicago Merchandise Mart, when completed in 1930, was the world’s largest building. It encloses more than 4 million square feet of commercial space. Designed by Alfred P. Shaw of Graham Anderson Probst and White Architects, the imposing steel structure, faced with limestone, overlooks the Chicago River. Regularly spaced piers that define the facade are punctuated with a central tower and corner turrets. Art Deco brass detailing highlights the building’s entrances and first floor windows. Ornamental stone busts depicting an American Indian line the parapets. Marble pillars with gold leaf, and murals by Jules Guerin adorn the lobby.